Diisobutylaluminumhydride → HCID 11954654, compound

HRID 563945Notes

Reaction equation

HRID 563945 reaction equation
C([O:3][C:4](=O)[CH2:5][CH2:6][C:7]1[C:8]2[C:19]([CH3:20])=[C:18]3[C:13]([CH:14]=[CH:15][CH:16]=[CH:17]3)=[C:12]([O:21][Si:22]([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23])[C:9]=2[O:10][CH:11]=1)C.[H-].C([Al+]CC(C)C)C(C)C>C(Cl)Cl>[C:25]([Si:22]([CH3:23])([CH3:24])[O:21][C:12]1[C:9]2[O:10][CH:11]=[C:7]([CH2:6][CH2:5][CH:4]=[O:3])[C:8]=2[C:19]([CH3:20])=[C:18]2[C:13]=1[CH:14]=[CH:15][CH:16]=[CH:17]2)([CH3:28])([CH3:27])[CH3:26]

Participants

4

Reactant 2

HCID 21225700DiisobutylaluminumhydrideHCID 45257631HCID 45257631, compound

Product 1

HCID 11954654HCID 11954654, compoundYield 98.5%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of 67.0 mg (0.162 mmol, 1.0 eq) of ester 17 in 1.60 mL of dry CH2Cl2 was stirred in a dry 5 mL round bottom flask at room temperature under argon. The solution was then cooled to −78° C. in a dry ice/acetone bath. Once cooled, 162 μL (1.2 M in toluene, 0.195 mmol, 1.2 eq) of Diisobutylaluminum hydride was added dropwise and the resulting solution was stirred at −78° C. for 30 minutes. While still cold, the solution was then quenched via the dropwise addition of 170 μL of MeOH followed by 670 μL of saturated aqueous sodium potassium tartrate (Rochelle's salt) added at once. The dry ice/acetone bath was then removed and the solution was diluted with Et2O and stirred for 20 minutes. The colorless solution was then filtered through CELITE. The CELITE was washed with Et2O and the combined organic fractions were washed with brine. The aqueous layer was further extracted with Et2O and the combined organic fractions were dried over MgSO4. Concentration yielded 58.8 mg (98%) of 18 as a colorless solid, Rf 0.72 (1:1 hexane:EtOAc). Mp: 152.5-153.6° C. 1H-NMR (500 MHz, CDCl3): 9.92 (1H, s), 8.31 (1H, m), 8.09 (1H, m), 7.47 (2H, m), 7.44 (1H, s), 3.29 (2H, t, J=7.3 Hz), 2.93 (2H, t, J=7.4 Hz), 2.91 (3H, s), 1.15 (9H, s), 0.27 (6H, s). 13C-NMR (500 MHz, CDCl3): 201.35, 143.46, 143.26, 130.19, 127.88, 125.80, 124.12, 123.86, 123.79, 122.72, 119.76, 118.44, 43.76, 26.24, 18.93, 18.85, 14.45, −3.85. IR (cm−1): 2927 (m), 2856 (m), 1724 (s), 1628 (m), 1461 (m), 1390 (s), 1247 (m), 1191 (m), 1117 (s), 988 (s), 826 (s), 786 (s), 760 (s). Anal. Calcd. for C22H28O3Si: C, 71.70; H, 7.66. Found: C, 71.34; H, 7.68.

Workup

  1. temperatureOnce cooled
  2. customWhile still cold, the solution was then quenched via the dropwise addition of 170 μL of MeOH
  3. additionadded at once
  4. customThe dry ice/acetone bath was then removed
  5. additionthe solution was diluted with Et2O
  6. stirringstirred for 20 minutes
  7. filtrationThe colorless solution was then filtered through CELITE
  8. washThe CELITE was washed with Et2O
  9. washthe combined organic fractions were washed with brine
  10. extractionThe aqueous layer was further extracted with Et2O
  11. dry with materialthe combined organic fractions were dried over MgSO4
  12. concentrationConcentration

Sources & evidence

ORD record
ord-074cd41a0bb84da5b3faf9f6e7e3a6b5
Source dataset
uspto-grants-2011_11
Patent number
US08067583B2

Reaction notes

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